The Android TV app called Cumulus TV requires an individual link to an XMLTV file for each channel.
Its a pain in the butt, but I can't simply give them the link to my full EPG list that you provide.

Is there a way to access the individual links to each channel's XMLTV file? I dread the idea of needing to enter each one, but that app has all of the other features I am hoping for so I'd love to be able to use it.

I also think, that you can enter the same url to every channel.
The magic happens in the m3u file by the tvg-ids.
If that app needs different xml urls for every channel none the less, then it's a crap.
Then please use GSE Smart IPTV on an Android phone.